import java.util.*;
class Example2_5{
   public static void main(String[] args) {
    int start =0,end,middle;
    int a[]={12,45,67,89,123,-45,67};
    int N=a.length;
    for(int i=0;i<N;i++){
      for(int j=i+1;j<N;j++){
        if(a[j]<a[i]){
          int t=a[j];
          a[j]=a[i];
          a[i]=t;
        }
      }
    }
    Scanner scanner =new Scanner(System.in);
    System.out.println("输入整数，程序判断该整数是否在数组中：");
    int number=scanner.nextInt();
    int count=0;
    end=N;
    middle=(start+end)/2;
    while(number!=a[middle]){
      if(number>a[middle])
      start=middle;
      else if (number<a[middle])
      end=middle;
      middle=(start+end)/2;
      count++;
      if(count>N/2)
      break;
    }
    if(count>N/2)
      System.out.printf("%d不在数组中.\n",number);
    else
      System.out.printf("%d在数组中.\n",number);
  }
}
